Circulating Tumor Cells and Late Recurrence in Hormone Receptor–Positive Breast Cancer
In a study reported in JAMA Oncology, Sparano et al found that a single circulating tumor cell (CTC) assessment was predictive of late recurrence in patients with hormone receptor–positive, HER2-negative breast cancer.
The study involved patients from a phase III trial of doxorubicin and cyclophosphamide followed by paclitaxel with bevacizumab (Avastin) or placebo in patients with HER2-negative stage II or III lymph node–positive and high-risk lymph node–negative disease, enrolled between 2007 and 2011, who had no clinical evidence of recurrence between 4.5 and 7.5 years after primary surgical treatment followed by adjuvant systemic therapy. Blood samples were obtained for CTC analysis in 547 patients at approximately 5 years after diagnosis, with a positive assay defined as ≥ 1 CTC per 7.5 mL of blood.
Risk of Late Recurrence
Among 547 women included in the analysis, late recurrence was observed in only 1 of 193 patients with hormone receptor–negative disease. The CTC assay was positive for 18 (5.1%) of 353 with hormone receptor–positive disease, with 23 (6.5%) of these 353 patients having clinical recurrence. Recurrence rates were 21.4% (7 recurrences per 32.7 person-years) in the CTC-positive group vs 2.0% (16 recurrences per 796.3 person-years) in the CTC-negative group.
On multivariate analysis, a positive CTC assay was independently associated with a significantly higher risk of recurrence in patients with hormone receptor–positive disease (hazard ratio = 13.1, 95% confidence interval = 4.7–36.3). Seven (30.4%) of 23 patients with recurrence had a positive CTC assay at a median of 2.8 years (range = 0.1–2.8 years) before clinical recurrence. CTC assays were positive for 8 (4.1%) of 193 patients with hormone receptor–negative disease; the 1 patient with recurrence was CTC-negative.
The investigators concluded, “A single positive CTC assay result 5 years after diagnosis of hormone receptor–positive breast cancer provided independent prognostic information for late clinical recurrence, which provides proof of concept that liquid-based biomarkers may be used to risk stratify for late recurrence and guide therapy.”
The study was supported by the National Cancer Institute, Breast Cancer Research Foundation, and Susan G. Komen Foundation.
Joseph Sparano, MD, of Montefiore Medical Center, Albert Einstein College of Medicine, is the corresponding author for the JAMA Oncology article.
The content in this post has not been reviewed by the American Society of Clinical Oncology, Inc. (ASCO®) and does not necessarily reflect the ideas and opinions of ASCO®.
